Ventilation



H. L. DOHERTY.

VENTILATION.

APPLICATION FILED DEC. 15, 191 5.

1,382,96 1 Patented June 28, 1921.

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VENTILATION.

APPLICATION FILED'DEC. l5. I916.

Patented June 28, 1921.

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VENTILATION;

APPLICATION FILED DEC. 15, 1916.

wi lmm H. L. DOHERTY. VENTILATION.

APPLICATION FILED DEC. 15' I916.

1,382,961 PatehtedJune 28, 1921.

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VENTILATION.

APPLICATION FILED DEC. I5, I9I6.

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' Patented June 28, 1921.

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H. L. DOHERTY.

VENTILATION.

APPLICATION Fl-LED 0Ec.15. 191a.

Patented June 28, 1921.

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VENTILATION.

APPLICATION FILED 050.15, I916.

Patented June 28, 1921.

8 SHEETS-SHEET 8- ATTORN EY UNITED" STATES PATENT OFFICE.

HENRY I. DOHERT'Y,

OF NEW YORK, N. Y.

VENTILATION.

(Bonfire-nation of applications Serial Nos. 638,867, No. 701,873, filed June 5, 1912, and Serial Nos.

Specification of Letters Patent. Patent d J 28 1921 cation filed December 15, 1916. Serial No. 137,107.

To all whom it may concern Be it known that I, HENRY L. DOHERTY, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Ventilation, of which the following is a specification.

This invention relates to ventilation; and it comprises a method of and apparatus for producing a constant flow of air to and from a building while maintaining a constant temperature in said building irrespective of whether said temperature be higher or lower than that prevailing outside said building, wherein the incoming air is caused to undergo temperature interchange with the outgoing air, and is also cleaned and scrubbed,by'means of circulating currents of water or other liquid, any deficit of heat or cold (as the case may be) remaining after such interchange being made up in other ways but advantageously by the use of power; all as more fully hereinafter set forth and as claimed.

Heating of buildings is of course a well developed art while positive cooling is seldom attempted save in the case of refrigerating establishments. Positive cooling is not used to any extent for ofiice buildings and the like. Ventilation is usually effected in a more or less haphazard manner, the general rule being that air is supplied to a room and allowed to escape as it will through the porosity of bricks and structural material, leakages at windows and the like. Where heating is by hot air, this air is heated in a furnace or the like and supplied to the rooms, the air already present being allowed to escape in any manner it may. Where heatingis by radiators and the like, as a rule exchange of air in a room is allowed to take care of itself. In all these methods, the heat carried by the escaping air is of course lost; there is no provision for recovering 1t.

In the present invention I have substituted for these more or less haphazard ways of heating and ventilating a positive method of ventilation wherein the temperature of the building or room is maintained at a fired point by interchange of heat between flowing incoming air and outgoing air. The temperature plane so fixed and maintamed may be higher than that of. the outs1de a1r, 111 which case the method may be considered a heating method, or it may be lower than that of the outside air in which case the method is one of cooling. In so doing, where the. building is to be maintamed warmer than the outside air, the heat units Whichare ordinarily wasted in the usual methods of heating and ventilat1on are picked up by the incoming air and restored to the room or building. I find that by the use of a simple heat interchanglng system it is as practicable to keep a bulldmg cool as it is to keep it warm; and w th the type of apparatus hereinafter described this change from heating to cooling may be done by simply adjusting a. valve or two; the process and apparatus operating in the same manner whether heat is transferred from the outgoing air to the ncoming'air (in warming) or from the ncrgming air to the outgoing air (in coolmg My invention is particularly useful in connection with cold storage plants, drymg kilns and houses, assembly halls, theaters and oflice buildings and the like.

In heating or cooling a building with theoretical heat interchange, the temperature of the building would of course remain fixed, whatever the rapidity of current of incoming and outgoing air. But theoretical efiiciency in heat interchange is not to be secured and there are, further, radiation losses. Heat is radiated from the windows and walls'of very warm buildings in cold weather, while in hot weather heat is radiated inwardly in the same manner. This unavoidable deficit in heat or in cold I make up in a suitable manner. As will be seen, in the case of heating a building w";

in the present manner, however, I merely require to make upthis deficit; not to supply an indefinite amount of heat units to be lost by being radiated and carried away from the building. The amount of heat therefore to be supplied is much lessthan in the ordinary methods of operation.

In producing the heat interchange between incoming and outgoing air currents I find it best to use circulating bodies of liquid which is advantageously water, since heat interchange can be carried farther between a gas and a liquid than between two gases separated by a metal wall; this being particularly the case where the differences in temperature between the air currents undergoing interchange are small; as is necessarily the case in ventilating buildings.

In the present invention therefore, in its most advantageous embodiment, I produce circulating currents of liquid which pass between the two air currents. The sameliquid circulating in a closed circuit, may first be brought into contact with one current and then with the other current; but I find it better to operate in a more special manner, using a plurality offiows of liquid and interchanging between pairs of such flows. In making up the deficit of heat or cold remaining after the interchange find it best to use pumping means located in the circuit and operating on vapors of the liquids used for heat interchange. W1th any pump operating on vapors, heat 1s of course developed on the compresslon slde and absorbed on the suction side. Use of power for imparting or withdrawing heat is practicable in this relation since after all it is merely a deficit which is to be made up; the main heating or cooling being done by heat interchange.

Advantageously I divide the operation of treating the incoming andthe outgoing a r into a plurality of successive stages. In this treatment, which for the sake of brevity I may call conditioning hereinafter, by the use of currents of water in direct contact with the air I am enabled to accomplish several other results than that of the heat interchange hereinbefore discussed. The incoming air is always more or less dusty and it IS desirable that it be cleaned and scrubbed. It is also desirable that the air supplled to the rooms have an adjusted moisture content; being neither too moist nor too dry. This adjustment and scrubbing to free the air of dust may both be effected by the liqu1d currents used for heat adjustment in the present method.

I shall now describe an advantageous embodiment of my invention as applied where the temperature to be maintained in the room or building is above that of the outer air. The outer air is drawn or forced in by a suitable pump or fan through a chamber where it is cooled and scrubbed by a bod of water circulating in a closed path. his path may include a filter for catching the accumulated dust and dirt. This body of water I cause to circulate through a metal heat interchanger of any suitable type; and on ghe other side of the metal walls in the heat interchanger I cause to circulate in a closed path a similar body of liquid, which is brought into intimate contact with the air current removed from the room. The second stated current of liquid abstracts heat from the outgoing air and transfers it through the heat interchanger to the first stated circulating body which then ives it up to the air which it is scrubbing. assin'g this scrubbing device the air next enters another chamber where it is brought into similar contact with another body of liquid traveling in a closed circuit. In this closed circuit is interposed a vapor chamber with which communicates a pump. Suitable connections enable this vapor chamber to be placed under either pressure or suction from said pump. In the present instance, it will be on the compression side of the pump. This body of liquidcompletes the warming up of the air and any deficit of heat which the air may have after undergoing the stated heat interchange will be here made up; being made up by the power of the pump. After contact with the two bodies of water in the manner stated, the air will of course be saturated with the moisture at the temgerature prevailing in the heating chambers.

0 much moisture is not desirable in air to be delivered to a room. I therefore run the apparatus in such a manner that the temperature at which the air leaves contact with the bodies of liquid is somewhat below that at which it is desired to enter the room and then filter out the mist of water which is usually present and reheat a little further. This reheating is best done by heat taken from the outflowing air from the room but may also be accomplished by the use of a small heater, such as a steam heater. In a similar manner outgoing air from the building in the instance just discussed is first used to raise the temperature of the conditioned air to get rid of the saturation mentioned, is then caused to flow through a spray chamber or the like where it gives up its heat to a circulating body of liquid which is the same as the first one hereinbefore mentioned; that which travels through the heat through another chamber wherein it is contacted with another current of liquid; this latter current of liquid traveling in a closed path including a vapor chamber which is on the suction side of the stated pump. The air gives up its heat to this body of liquid and the pump removes vapors from the body of liquid and transfers them to the compression in the manner before stated. The outgoing air may now be allowed to escape. In cooling the building the working of the apparatus is simply reversed so that the air now travels in the reverse direction. As just described,'the heat of the outgoing air was transferred to the incoming air. In this cooling operation the heat of the incoming air is transferred in exactly the same manner to the outgoing air. The operation is exactly the same.

In theaccompanying illustrations, I have shown, more or less diagrammatically, organizations of a paratus elements adapted for use in the escribed process. In this showing:

Figure 1 is a diagrammatic plan of one assemblageof apparatus elements for carrying out my process;

Fig. 2 is a diagrammatic illustration of a somewhat different form of apparatus;

Fig. 3 isa vertical diagrammatical section through a building showing the arrangementof the air conduits and a portion of the operating plant; i

Fig. 4 is a more or less diagrammatic plan of an actual working construction and arrangement of the apparatus shown diagrammatically in Fig. 2; a

Fig. 5 is a longitudinal section of the portion of the apparatus for the treatment of incoming air taken on line 5-5 of Fig. 4;

Fig. 6 is a similar longitudinal section through the apparatus from the discharge side on line 6-6 of Fig. 4-;

Fig. 7 is a vertical section through the heat transferring apparatus J;

Fig. 8 is a similar view of a slightly modified form of heat transferring apparatus J;

Fig. 9 is a partial section in partial elevation of the washer;

Fig. 10 is a vertical section through the spray chamber; r

Fig. 11 is a section through the manometer' Fig. 12 is a longitudinal section of the water eliminator;

Fig. 13 is a perspective view of the venti-' lating system illustrated in Fig. 2, showing its relation to the rooms of the building to be heated and ventilated.

Referring to the drawings (Figs. 3 and 13), 1, 2, 3, 4, 5,. 6, 7, 8 and Qindicateseveral rooms of a building. A A A A}, A A, A, A and A indicate one set of air flues leading to registers D D D D D D D D and D set in the base boards of the rooms. B B B B B B, B B and 13", indicate another set of air flues leading to registers C C C, C, C C C, C and C set near the ceiling of the corresponding rooms, the registers of both these sets of air flues advantageously being set in the walls of the rooms so that the air will always be discharged into the rooms in a horizontal direction. 10 indicates a trunk main to which the flues A are connected, while 11 indicates the trunk main to which the flues B are connected. The trunk mains 10 and 11 are connected with the heating chamber 37 by the conduit 70. Valves 71 and 72 permit establishing or shutting off the communication between and 10 and 11 respectively. A similar connection 73 having branches 74 and provided with valves 76 and 77 and connected to conduits 10 and respectively, permits establishing or shutting off communication between 10 and 11 and the washer 31 as shown in Figs. 2, 6 and 13 or spray chamber 60 in the modification shown in Fig. 1. When the apparatus is working as a heater, the valves 72 vand 76 are open, and 71 and 77 are closed.

dampers on the flues B, while F F F F,

F F", F, F and F are dampers on the flues A. G G G G G G, G Gr and G are tubes running from the tube 13 of the pressure indicator to the respective rooms 1, 2, 3, etc. and are each provided with valves respectively designated by adding the letter a to the numeral designating the respective tubes.

14, 15 and 16 are tubes running from the tube 17 to points on the side wall of the building. These tubes terminate at a middle point of the side wall of the first, second and third stories respectively and are in free communication with the outside air. Corresponding pressure tubes 18, 19 and 20 and 21, 22 and 23 run to the middle portion of the end wall of the respective stories. Another set (not shown) runs to the other side wall of the building. Each of these pressure tubes is provided with a cook, 14, 15*, etc. The trunk tubes 13 and 17 are connected respectively to the pressure chambers 24 and 25 on the magnifying manometer. As shown in Fig. 11, one of the two sides of the manometer is filled with oil and the other with water. The line of division between the two when 24 and 25 are under equal pressure should be at the middle of the oil leg which is numbered 0 on the scale. The two pressure chambers 24 and 25 have areas which are large relative to the cross section of the U-tube. As will be readily perceived, the relative level of the liquids in the respective chambers 24 and 25 will depend upon the pressure difference between them. For instance, if the pressure in 24 is the highest, the level in 24'will fall, while the level in 25 will rise. The line of division between the oil and water will therefore fall through a length of the oil leg of the U-tube which will have a volume equal to that of the displaced oil. The amount of movement of the line of demarcation relative to the difference in pressure will manifestly do end upon the ratio of the cross section oi the other chamber 25- (if the difference is measured in terms of the water column) to the cross section of the U-tube. I am thus able to open the cock on the pressure tube connecting the oil chamber of the manometer (in the arrangement shown) with any room and the other chamber of the manometer with the corresponding pressure tube to the atmosphere, to detect very small differences in pressure between any room and the atmosphere. Since it is necessary for the successful operation of my invention that there shall be no short circuiting of air from the atmosphere to the room or vice versa, it is very important to keep the pressures in the rooms as nearly equal to that exerted by the atmosphere on the exposed wall as possible. Noting pressure conditions from the manipulations of the manometer, the operator can easily bring the pressure to the requisite balance by operating dampers E and F, or if necessary, regulating the speed of the fans.

' 27 is the downcast air conduit conducting the fresh intake air, while 28 is the upcast conduit for the impure air discharged from the building.

The fan 29, Figs. 1, 2, 4 and 5, draws the fresh outside air through the conduit 27 and forces it into the washer 30. Here it is contacted with water which usually has substantially the temperature of the air discharged from the building. The water for scrubbing in 30 may be directly contacted with the discharged air in washer 31, or the scrubbing water for circulation through the respective chambers may be kept separate and the heat transferred from one body of water to the other in a heat interchanger 32. Interchanger 32 may be simply of the tubular heater type or of any other type of apparatus preferred in which two bodies of water are caused to flow along opposite sides of metallic surfaces. I have found it advantageous to use an apparatus in which it is possible to permit the hotter current to enter at the top and the cooler current at the bottom. In this way I avoid convection currents and so maintain a maximum temperature difference between the two currents during their flow through the apparatus.

In 30 the fresh air is either heated or cooled according to whether the outside air is hotter or cooler than the inside air, and thoroughly scrubbed for the elimination of dust. 30 may be of any construction which will insure thorough contact of air and water or saline solution. It may be of such design that the air is forced to pass through a number of water curtains 30' (Figs. 4 and 5).

In the form of construction shown in Fig. 9, the chamber 30 contains a number of tiers of horizontal transverse troughs 62, the troughs placed. The 11 per edges of the troughs 62 are notched. he feeder trough 63 runs transversely to the trou hs and narrow vertical slots located just a We the troughs of the first tier so that water discharges into the upper troughs from ,each side of the feeder trough. The water overflows from the troughs of the upper tier and in each case cascades or rains down to the two troughs of the next tier placed to right and left of the particular trough considered. The air enters at the bottom and passes up to the top of the chamber and is thus forced to pass through a large number of water currents formed by the water overflowing from the troughs. Circulating pumps 64 and 65 supply the scrubbing solution to the Washers 30 and 31.

From 30 the air passes through conduit 100 to the spray chamber 33. Here it is subjected to contact with a jet of steam or warm or cold water asdescribed below according to the temperature of the atmosphere. The spray chambers 33 and 60 are designed to bring the air into intimate contact with the steam or liquid supply-the cold liquid being used when the apparatus is being used as a cooler. Any apparatus which is capable of reducin the liquid to a. very fine spray may be use If the system is acting as a heater, live steam may be blown into the air from steam pipe 34 which is provided with a regulating valve 35. This steam serves both to heat the air and at the same time to humidify it. The quantity of steam used should be that which will raise the air from the temperature at which it leaves the washer 30 through conduit 100 to about 60 F., more or less. The air discharging from 33 usually carries a heavy fog of condensed steam or of fine particles of water spray, according to whether the apparatus is being used as a heater or cooler.

This spray is eliminated in the water eliminator or separator 36. 36 may be of any approved construction. Any good type of tar separator used in purifying illuminating gas may be made to answer the requirements. The one shown is made up of a large number of corrugated plates 36' (see Figs. 12 and 13) set up so that their surfaces are parallel with each other and leave an interval of about one-half inch between them. In operation, the air passing between the curved surfaces of the plates at a rapid rate develops considerable centrifugal effect upon suspended water particles (the corrugations are made about 6 to 8 inches deep) which are thrown against the walls of the passage. These are in operation covered with a thin film of the liquid which serves to separate and retain any dust particles which may have escaped precipitation in the washer.

:neeepei pipe 34: serves to sup- If, as conditions may be is able to raise the The steam from the plement the action or" the washer. with some temperature the case, the Washer 30 air to about the steam injection may be omitted. it is used when the washer or other means for taking heat from the outgoing air current (as is generally the case) is not able to properly condition the air. To do this it is necessary to communicate to the air per unit weight an amount of moisture which, when the air is at the temperature at which it is supplied to the rooms, will give it the relative humidity desired. This usually from to per cent. according to the preference of the individual. in cold weather a rather high humidity is preferable since it supplements the warming effect of the hot air by reducing the amount of heat from the bodies of the occupants through the excessive evaporation oi. moisture. In warm weather, on the other hand, a low humidity is desirable since it promotes the direct cooling of the bodies of the occupants by increasing the evaporation of the perspiration. By using a proper quantity of steam in 33 it is always possible to prop; erly condition the air no matter how cold the external atmosphere.

When steam is not easily available the conditioning of the air may be ei'lected by loading the air with a heavy mist or log in the spraying chamber and, icy-passing the water eliminator, passing the air current to the heating coils 37. Here the water will be evaporated by the heat from the coils as the air rises in temperature and conse quently increases in vapor-carrying capacity. It is, of course, necessary in this method of operating to see that only the proper weight of water per pound oi air is loaded on the latter in the spray chamber.

After passing through or around the water eliminator, as the case may be, the air passes to the coils 37. Here it is heated to a temperature of about 65 to 75 according to the temperature desired in the rooms. If the air be saturated with vapor at 60 and then raised to 72 it will have just about the humidity desirable.

From 37 the air passes through pipe 70 to the air trunk conduit 11 and from 11 it is distributed to the various fiues B B 13 B, B B, B, B and B leading to the upper registers C of the several rooms, the heated air spreads across the room in contact with the ceiling and gradually descends as the lowest stratum oi air is removed and fresh air flows in above, without mixing to any great extent with the partially contaminated air occupying the lower part of the room. By thus preventing convection currents and positively renewing the air of therooms instead of constantly diluting a partially contaminated atmosphere, as is done in the ordinary method of building ventilation, 1 am able to secure a given.

standard of purity in the room atmosphere 7 steam discharges nozzle 61 in the return main, thus aiding the a circulation oi the water as well heating it. The hot water then flows through the pipes 68 to the radiators 69 in the rooms. As shown, these are located in an enlarge ment of the air line and heat the air just as the latter discharges into the rooms. By this arrangement I avoid the establishment of local conventions which would interfere with the movement of the air through the rooms according to my plan. it is true that by thus locating the radiators, ll prevent the direct heat radiation to the bodies of the occupants which takes place when the radiators are located in the rooms. But heating by the radiators is purely auniliary and they are of small surface, this drawback is practically negligible.

The air finally reaches the lowest level or the rooms and discharges from the same through the registers D into the fines A of the respective rooms, thence through the trunk main 10 to the spray chamber 38 or the washer Ell accordin to the form of apparatus. /V hen using the apparatus of Fig. l as a heater and" ventilator the spray Chaim" ber 60 :lulfils no function than that oil providing passage of the outgoing air to the washer 31, which is of the same construe tion as washer 30. Still considering the apparatus as a heater the outgoing air in washer 31 is subjected to scrubbing by water which has been cooled in 32 by the cold water flowing from the washer 30. The cooling of the air causes condensation of more or less of the water vapor which the air carries out of the rooms-the amount condensed depending upon the degree of cooling to which the air is subjected in 31.

By proper designing and operation the heat given up to theincoming air in 30 is thus in great part withdrawn again in 31 from the outgoing air. The evaporation in 30 and condensation in 31 requires that at intervals a proper proportion of the water from the washer 31 circuit shall be transferred to the washer 30 circuit. With theoretically perfeet working of the heat interchanging appa ratus I the total expenditure of heat would be represented by the heat supplied by the coils 37 and the greater or less amount of Lilli-ii Hill conditions, will be less than 40 percent.

heat required to discharge the air in the saturated condition instead of in the par- 'tially saturated condition in which it is received into the system. The latter heat quantity includes the latent heat of the vapor carried by the effluent air over that carried by the air at the intake and any excess of sonsible heat due to the fact that, owing to 11m perfect working of the apparatus, the temperature of the efiiuent air is seldom or never as low as that of the air at the intake. This ideal can, of course, never be completely realized in practice. With even an per cent. efiiciencyof heat transfer from 31 to 30, however, the T. U. required to heat a given building, even under severe winterf' 0 the B. T. U. that would be required with the usual methods of heating.

The air discharging from 31 passes to the exhaust fan 40. From 40 the air passes through the up-cast conduit 28 to some level above the roof of the building where it is discharged into the atmosphere.

'When working as a refrigerating and ventilating process in the summer time, the action of the apparatus is as follows:

The warm atmospheric air, as before, is drawn into the system through conduit 27 by the fan 29 and forced throu h the washer 30. Here, as before, it is scrubbed by water,

only in this case the water is initially cooler than the air by a range of temperature depending upon the excess of atmospheric temperature over the room temperature. The water is cooled in the interchanger 32 by the counter circulation of the water from the Washer 31 through which the relatively cold air discharging from the rooms passes. Besides abstracting sensible heat from the air, in this case the washer 30 must absorb the latent heat of the considerable quantity of water vapor condensed from the fresh air. Owing to inefficiency in heat transfer and to the heat increments which the air receives in the building and conduits, it is never possible to maintain a given temperature (say 72) in the building, even though once established, by the unaided action of the washers 30 and 31. In order to maintain the rooms at the desired temperature it is therefore necessary to exert on the fresh air an additional refrigerating effect. This end I accomplish by transferring heat mechanically from the incoming to the outgoing air current through the medium of the heat transferring apparatus J.

I have lettered as J a'particular heat transferring mechanism wherein a vapor pump is located between two chambers one of which on the suction side thepump, temporarily at least, serves as an evaporator, while the other which is temporarily at least on the pressure side of the pump, serves as a condensing chamber. By reversing the connections the evaporator becomes a condenser and the condenser an evaporator. lln the chamber on the suction side of the pump, the pressure being lowered, there is evaporation and cooling while in the chamber on the pressure side there is condensation of the liquid and development of heat. Tn both the evaporator and the condenser it is desirable to have a large surface of liquid exposed to the atmosphere of the chamber under pressure or suction.

The heat transferrer J of Fig. 7 comprises an evaporator, 41, a condenser, 42, and a vapor pump, 43. The evaporator 41 has a vaporizing chamber, '44, containing a plurality of troughs, 45, a barometric leg,

46, and the reservoir and seal-tank 47. The spray chambers 33 and 60 are also a part of the refrigerating apparatus since it is in 43 the pressure in 44 is maintained at about .254 pound which corresponds to the maximum tension of Water vapor at 60 F. Since the water leaves the spray chamber at a much higher temperature, depending upon the temperature at which the air discharges from 30 and the volume of water circulated, etc., on entering the chamber 44 it immediately boils at the expense of its own heat. As the water falls from trough to trough more and more of it is vaporized, the residuum approaching closer and closer to the temperature corresponding to the vapor tension in the chamber (preferably .254 pound absolute) until it finally reaches the bottom of the chamber 44, under the assumed conditions, usually at a temperature of 60 F. From the chamber 44 it gradually descends through the barometric tube 46 as the water is drawn from the tank 47, until it finally.-

reaches the tank and is pumped thence again to the sprays of chamber 33 through pipe 47. The vapor formed in 44 is forced by the vapor pump 43 into the condenser chamber 49 of condenser 42. 49 contains a filling of troughs, 50, similar to the troughs 45, the upper tier of 50 being fed from the'transverse trough 51. Water from the spray chamber 60 on the exhaust air circuit is drawn into the trough 51 and from thence passes to the upper tier of troughs 50. From the troughs 50 of the upper tier the water overflows and cascades to the troughs of the tier below. These are placed halfway between the troughs of the upper tier so that each trough receives approximately onehalf of the overflow from the troughs of the chamber 60. It the temperature first tier on each side of it. The water passes thus from tier to tier in intimate contact with the vapor filling the chamber 49, taking up heat from the vapor and condensing it. An air pump, 55, removes from the chamber 49 of 4:2 or from chamber M the air which is carried into the chamber by the two currents of circulating water. The circulation of Water is maintained suiticiently rapid to keep the chamber at a temperature of about 80 (or slightly above if necessary). The condensed vapor mingles with the Water circulating through 49 and 60, and the current descends through the barometric tube of 42 into the seal-tank 54 and is pumped thence back to the spray at which the Water leaves the condenser chamber i9 is maintained at about 80 F. the vapor pump is only working against a ressure difference of .248 pound per square inch and the amount of power required is not serious. An air pump, 55, removes from 49 such air as is carried thereinto by the two bodies of circulating water-the air being absorbed by the water in the two chambers 33 and 60.

In Fig. 8 l have shown an alternative form of the structure of Fig. 7 like elements having like reference numbers. The difference is mainly in the form of interior subdividing or distributing device for bringing into intimate contact the liquid and the atmosphere of the chamber. In this form the water instead of being delivered on the trough-like elements of Fig. 7 is delivered into a series of perforated troughs 45 of chamber 41' and perforated troughs of chamber 42 over which it runs from top to bottom giving a film'like exposure of the liquid to the atmosphere in the chamber. The barometric legs 46' are shown as passing into wells 47 and 54: in lieu of the tanks 47 and 54 of Fig. 7. Otherwise the two structures are the same.

As stated before, the air in passing through 33 is subjected to a fine spray of cold water, the water being obtained as described above. The spraying device in the chamber 33 consists oi banks of spray nozzles 56 which receive water under pressure and spray it into the air current passing through chamber 33. The-contact of this spray with the air from the washer 3O thoroughly cools the same. Usually the air will leave the washer 30 saturated or nearly saturated after depositing a large part of its vapor contents and parts with still more water in 33. Arrangements must be made to have the air discharge from 33 at such a temperature that the vapor carried by the saturated air will correspond to the proportion of vapor desired in the rooms.

On leaving 33 the air will be heavily loaded with fog or spray. To remove this it is passed through the water eliminator and'is simply left in the air circuit to avoid the labor of changing the arrangement of the apparatus when changing from a heating to a refrigerating operation. The air next passes to the trunk main l0 and from 10 through the flues A A etc., to the lower registers D of the rooms, Discharging from the registers D, the air spreads across the room as a fairly horizontal stratum which gradually rises as it is displaced by fresh air from D. The air discharges from the rooms through the upper registers and flues B to the trunk mean 11, which is, in this case, connected to the spray chamber 60 on the exhaust side of the circuit or to the washing chamber 31 in the apparatus of Fig. 2. It is to be noted that by introducing the cold air into the rooms at the bottom I avoid to a great extent the mixing of the fresh air with the partially vitiated air in the room, just as in the heating operation I avoid the same thing by introducing the hot air at the top of the rooms. While the air usually enters the tines A at approximately 60 to owing to the heat which it receives in passing through the fines from the relatively hot walls, it discharges into the rooms at about Tn passing through the rooms it is increased in temperature by heat conducted from the atmosphere and that generated by the individuals in the rooms, and at the same time picks up the moisture and contaminating matter exhaled by the occupants.

In the spray chamber 60 the air is sub-y jected to scrubbing by the atomized water drawn off from the tank 54 of the condenser 42 of the heat transterrer J and pumped to the sprays of the chamber 60. Since the outgoing air usually has a humidity of only about 70 per cent. and is at a temperature of only about while it leaves the spray chamber 60 at a higher temperature and saturated with water vapor the combined effects of the evaporation and transfer of sensible heat to the air from the water spray chamber 60 is to impart an amount of heat equivalent to the heat liberated in the condensation of the water vapor pumped from the evaporator 41 to 42 by the vapor pump 43. The unevaporated water is drawn from the bottom of the spray chamber and drawn back through the pipe 49 to the top of the condenser chamber 49, where it condenses the vapor pumped into 49 from 41.

Under extremely high atmospheric temperatures the air in 60 may experience a rise of temperature of from 2 to 5. It is seldom, however, that it is necessary to raise the temperature more than a couple of. de-' grees and, as a rule, the saturation of the passes through the air with moisture will furnish ample cooling effect to cool the condenser water. It is desirable that in 60 the air to be saturated to the maximum extent so that the maximum possible proportion of, the cooling may be performed by evaporation, thus permitting the air to enter the washer 31 at the lowest possible temperature.

From 60 in the apparatus of Fig. 1 the air passes through a spray separator similar to that used in chamber 36 and enters the washer 31. This is similar in construction to 30 and requires no further description. Water which has been heated inthe heat interchanger 32 by the water warmed by the incoming air in washer 30 is pumped into the feed trough 63 of washer 31, passes to the upper tier of trou hs 62 and cascades from trough. to trough orming water curtains through which the air must pass. The intimate contact between air and water causes a portion of the sensible heat of the water (which should be within two or three degrees of the temperature of the outside air) to be transferred to the air. Since the increase of the vapor carrying capacity of air increases very rapidly with the temperature above -an increase intemperature from 70 to causing an increase in vapor carrying capacity of 40 per cent. of its capacity at 7 0, while a temperature rise of from 80 to causes an increase in carrying capacity for vapor of over 34 per cent. of the capacity at 7 0-the fact that the air usually enters the washer practically saturated does not interfere with the evaporation of more water in 31. The conditions of operation both in the spray chamber and in the washers depend upon the temperature difference between the building and the external air as well as upon the actual temperatures; but as a rule the cooling efiect in 31 through evaporation much exceeds the cooling effect by conduction. As a consequence, the rise in temperature of the air in passing through 31 is usually not as great as the fall in temperature of the oppositely flowing water current.

From 31 the air passes to the exhausting fan 40 and from there to the up-cast conduit or stack 28 and discharges into the atmosphere.

The structure of Fig. 1 and Fig. 2 represent methods of transferring heat differing somewhat in detail. Supposing the apparatus to be warming incoming air, in the structure of Fig. 1 the warmest outgoing air, that passed through 60, gives up its heat to the warmer incoming air, that coming through 33 by means of the compression suction system J already described, while the less warm outgoing air, that in 31, exchanges heat with the coldincoming air, that in 30, by means of the flowing water system I. In Fig. 2 this arrangement is, so to speak, re-

versed since in the structure of Fig. 2 the cold incoming air, that in 30, exchanges heat with the warmest outgoing air, that in 31, by means of the flowing water circulation T, while the somewhat cooled outgoing air, that in 60, transfers heat to the somewhat warmed air, that in 33, through the compression suction system 3'. More specifically, as the apparatus is shown in Fig. 1 the air in 30 is exchanging heat with the air in 31 by means of the water circulation. The same body of water may go from 30, by propelling or drawing, by pump 64 through by-pass 200 and 202 to 31 and thence back to 205 and by-pass 201 to 30 the valves 82 and 83 in the heat interchanger 32 being closed; or

it different bodies of water are used the Water passes through 64 to the heat interchanger 32, the valves in 200 and 201 being closed and the valves 82 and 83 being open. Here it exchanges heat with water flowing on the other side of the heat interchanger by means of pipes 202 and 205. The exchange of heat between 33 and 60 is eil'ected, the apparatus being in the act of warming up incoming air, by heating such air in 33 by somewhat warmed water from 47 passing to 33 through pipe 47 and returning to 44 by means of pipe-44 Part of the warm water may be by-passed through a pipe 47 tothe coils 37 and returned to the pipe 47 through a return pipe 47. Suitable valves 47 47* and 47 are provided in the pipes 47, 47 and 47 forcontrolling the amount of water by-passed. While the operation pump 43 is extracting vapors under suction and delivering into 44 it would be also delivering heat to 44. Similarly, water from 60, which has been warmed by the outgoing air, passes through 49 to suction chamber 49 where it yields vapor and heat and passes to 54 thence going to 54 back to 60.

In Fig. 2, presuming as before that the apparatus is heating up incoming air, the air first passes into 30 where it is contacted with warmer water. This water, if a single body of water is used, comes from chamber 31 exposed to the warmest outgoing air and extracts heat therefrom. Between 31 and 30 it flows in continuous cycle by means of pipe 204, by-pass 201, by-pass 200 and pipes 202. If different bodies of water are used for heat interchanging, then the water from 30 flows through pipes 84 and 84, the valves in 200 and 201 being closed, in continuous circuit through the heat interchanger where it exchanges heat with water similarly flowing in continuous circuit to and from 31 through conduits 202' and 204. At the same time heat is being interchanged between 31 and 33 by the compression-suction system J. The apparatus being used to heat the incoming air, somewhat heated water passes into 33 from hot well 47 by means of pipe 47, while water is returned to 44 through. 44*. Part of the warm water may be by-passed through a pipe 47 tothe coils 37 and returned to the pipe 47 through a return pipe 47. Suitable valves 47, 47 and 47 are provided in the pipes 47, 47 and 47" for controlling the amount of water by-passed. In this operation, pump 43 is delivering heat and compressed vapors into 44. Simultaneously, the air in 60 gives up some of its heat to flowing water which passes through 49 into suction chamber 49 where it gives up heat and vapors where it passes to cold well 54, being, delivered back to 60 from this cold well by 54.

It will be apparent that the fundamental idea underlying my process is the transfer from the outgoing to the incoming air, or vice verse, of the maximum possible quantity of heat,- while at the same time providing for the establishment of the proper condi-' tion of humidity of the air. To aid this heat-transfer when using the apparatus as a refrigerator the power of the air to carry latent heat through the medium of its water vapor is utilized to the greatest possible extent.

It is obvious thatthe temperature conditions in the different portions of my apparatus will vary with the variation of the temperature of the outside air, as well as with the difl'erence between this and the temperature in the rooms. Therefore it is to be understood that the temperatures which I have given for the air in different portions of its circuit are simply given in the way of illustration and are not to be construed as lim iting my invention to working within the exact temperature limits given.

What I claim is l 1. The process of ventilating bulldings which comprises passing air currents into and out of the building and transferring heat from the outgoing to the incoming current or vice versa through the medium of a liquid, while. bringing the incoming current to a standard degree of absolute humidlty.

2. The process of ventilating buildings which comprises passing air currents into and out of the building and transferring heat from the outgoing to the incoming current or vice versa by contacting first the warmer of the said currents and then the other of the said currents with water maintained in circulation between the two currents, while bringing the incoming air current to the desired degree of absolute humidity.

3. In a process of ventilating bulldlngs the step of bringing the air for ventilatlon to the proper conditions of temperature and humidity which comprises transferring heat from the outgoing to the incoming air currents, saturating the incoming air with water vapor and raising the temperature of the 'said incoming air current after it has been body of water to condition the temperature and humidity of the air.

5. The process of ventilatin and regulating the temperature of a building which comprises passing air currents into and out of the building, transferring heat from the outgoing air current to the incoming air current or vice versa by contacting both of said currents with separate bodies of water, establishing heat transferring relationship between the said two bodies of water, and continuing the circulation of the respective bodies of witer in closed cycles to treat the respective air currents.

6. They process of ventilatin and regulating the temperature of a building which comprises passing moist air currents into and out of the building, transferring from that one of incoming and outgoing air currents which has the higher temperature, to the other current, the major portion of the heat sensible and latent which it carries, condensing moisture from the initially warmer of the air currents and evaporating moisture into the initially cooler of the air currents.

7. In the ventilation of a building, the process which comprises drawing in an air current, subjecting the said air current to scrubbing by water, at such temperature as will transfer heat to said air, transferring to another body of water the temperature modification occasioned in the first body of water by the contact of the said incoming air therewith and subjecting an outgoing air current to scrubbing by the said second body of water.

8. In the. ventilation of buildings, the process of bringing an incoming a1r current to the desired condition of temperature and humidity which comprises transferring from an outgoing air current to the incoming air current the maximum practicable quantity of the excess heat in the said outgoing air current over the said incoming air current, through the medium of a liquid, introducing a jet of steam into the said incoming air current, and subjecting the said air to a further heating by contact with heated surfaces.

9. In the ventilation of buildings, the

process of bringing an incoming air current to the desired condition of temperature and humidity which comprises scrubbing the said incoming air current with a body of water which has itself previously been heated by heat abstracted from an outgoing air current, injecting into the said incoming air current, after the same has been subjected to the said scrubbing operation, sufficient steam scrubbing the incoming air current with water which has been heated by heat abstracted from an outgoing air current, introducing steam into the said incoming air until a temperature corresponding to the dew point of the properly conditioned air is reached, separating from said air any suspended water particles that may be left therein after treatment with said steam, subjecting the said air to a third heating to raise said air to a temperature suitable for heating the said building, scrubbing the outgoing air current with a second body of water, said water being at a lower temperature than the initial temperature of the said outgoing air current, and transferring the heat absorbed by the said second body of water to the said first body of water.

11. The process of conditioning air for ventilation which comprises heating the cooler one of intake and exhaust currents by heat transferred from the warmer current, and bringing the intake current to the desired temperature condition by evaporating water in heat-transferring relationship therewith or condensing water vapor in heat-transferring relationship therewith, according to whether the initial temperature of the intake current is above or below the temperature of the conditioned air.

12. The process of conditioning air for ventilation which comprises heating the cooler one of intake and exhaust air currents by transferring heat from the warmer to the cooler of said currents, and finally conditioning the said intake current by evaporating water in heat-transferring relationship therewith to cool said intake current and condense water vapor therefrom or by condensing water vapor in heat-transferring relationship with said intake current while contacting said intake current with water to heat said current and to add water vapor thereto, according to whether the initial temperature of the said intake air is below or above the temperature of the conditioned air.

13. In the process of conditioning air for ventilation, the stepof transferring heat between intake and exhaust air currents in the direction "of the current having the lower temperature which comprises transferring heat from the one of said currents having the higher temperature to water by directly contacting said air with said water, and transferring heat from said water to the one of said currents having the lower temperature by directly contacting said water with the said air current ha ving the lower temperature. y

14. In the process of conditioning air for ventilation the step of transferring heat from that one of intake and exhaust air currents having the higher temperature to the other of said currents which comprises transferring heat from the said air current having the higher temperature to water and then transferring heat'from said water to the one of said air currents having the lower temperature.

15. The process of conditioning air for ventilation which comprises transferring heat from that one of intake and exhaust air currents which has the higher temperature to a body of water, transferring heat from said body of water to a second body of water and transferring heat from said second body of water to that one of the said intake and exhaust air currents which has the lower temperature.

16. The process of conditioning air for ventilation which comprises contacting that one of intake and exhaust air currents which has the higher temperature with a body of liquid having a lower temperature than said higher temperature air current, transferring heat from said body of liquid to a second body of liquid, contacting said second body of. liquid with said air currerit having the lower temperature to heat said air current, and spraying water into the said air current having the lower temperature..

17. The process of conditioning air for ventilation which comprises contacting that one of intake and exhaust air currents which has the higher temperature with a liquid which is at a lower temperature to condense a portion of the water vapor of said first mentioned air current to cool the same and toheat said liquid, contacting said heated liquid with the said air current having the lower temperature to heat said current, and.

spraying water into said incoming air current to add water vapor to said current.

18. The process of conditioning air for ventilation which comprises continuously passing a body of water into contact with that one of intake and exhaust air currents which has the hi her initial temperature, and removing the body of water from the air current, continuously evaporating part of the body of water removed from said air I current, continuously condensing the vapor from said body of water to maintain rapid evaporation of said water, continuously circulating a second body of water into contact with said condensing vapor and into contact with that one of said currents which has the lower initial temperature, whereby heat is transferred from the first to the second of said air currents.

19. The process of conditioning air for ventilation which comprises continuously circulating a body of water into contact with that one of intake and exhaust air currents which has the higher initial temperature, continuously withdrawing vapor from part of said body ofwater while it is out of contact with said air current, continuously circulating a second body of water into contact with vapor from said first bod of water, and then contacting said second body of water with the initially cooler of said air currents, to heat the same.

20. In a ventilating system having incoming and outgoing currentsof air, the process of conditioning the incoming current of air which comprises maintaining a partial vacuum in a closed chamber containing water, maintaining a lower vacuum in another closed chamber also containing water, bringing water from the first of said closed chambers into intimate contact with one of said air currents, bringing water from the other of said closed chambers into intimate contact with the other of said air currents and transferring vapor from said lower vacuum chamber to said partial vacuum chamber.

21. The process of conditioning air for ventilation which comprises maintaining in a closed chamber a pressure such as will cause water to boil at a temperature below the desired temperature of the conditioned air, circulating water from said closed chamber into contact with that one of intake and exhaust air currents which has the higher initial temperature, transferring vapor from said chamber to a second chamber, maintaining in said second closed chamber a pressure such as will cause water to boil at a temperature above the desired temperature of the conditioned air, and circulating water from said second closed chamber into contact with that one of said air currents which has the lower initial temperature.

22. The process of conditioning air for ventilation which comprises maintaining in a closed chamber containing water a partial vacuum such as will cause water to boil at a temperature below the desired temperature of the conditioned air, continuously circulating water from said closed chamber in contact with that one of intake and exhaust air currents which had the higher initial temperature and then back to said closed chamber, maintaining in a second closed chamber containing water a pressure corresponding to the saturation pressure of water vapor at a temperature above the desired temperature of the conditioned air, transferring water vapor formed in said first chamber into said second chamber, continuously circulating water from said second closed chamber into contact with that one of said air currents which has the lower initial temperature, and returning said cooled water to said second closed chamber.

.23. The process of conditioning air for ventilation which comprises continuously circulating water into contact with that one of intake and exhaust air currents which has the higher initial temperature, causing-a portion of said water to evaporate under a pressure at which the water will boil at a temperature below the desired temperature of the conditioned air, continuously trans ferring water vapor formed by said evaporation into contact with a second body of water maintained at a pressure above the pressure prevailing in said first closed chamber, contacting said second body of water ,with that one of the said air currents which has the lower initial temperature, and maintaining a closed circulation of said water between said second body and said lower temperature air current.

24. The process of conditioning air for ventilation which comprises maintaining in a closed evaporating chamber an absolute pressure such as will cause water to'boil at a temperature below the desired temperature of the conditioned air, continuously circulating water, first, into contact with that one of intake and exhaust air currents which has the higher initial temperature, the initial temperature of said water being below that of said air current, and, second, back to said evaporating chamber, continuously transferring vapor formed in said evaporating chamber tov a condensing chamber which is maintained at a pressure above that of said evaporating chamber, circulating a second body of water through said condensing chamber, withdrawing water from said condensing chamber and contacting said water with that one of? said air currents which has the lower initial temperature to heat said air and to cool said water, the rate of circulation of said water relative to the rate of flow of said air being regulated to that which will cause a heat transfer to said air from said water.

25. The process of conditioning air for ventilation which comprises maintaining a partial vacuum over a barometric column of water, continuously withdrawing water from the lower part of said barometric column and bringing said water into contact with one of intake or exhaust air currents, the temperature of said water being lower than the temperature of said air current, conducting the so-heated water back to the top of said barometric column to vaporize a part III.

content, continuously transferring the so formed water vapor into a barometric column condenser, passing water through sa1d condenser, continuously withdrawing water from the lower part of the barometric column of said condenser at substantially the same rate that water is added to said column at the to thereof, contacting the water being with rawn with the other of sald a1r currents to transfer heat to said latter air current.

26. The process of conditioning air for ventilation which comprises heatin an intake air current in two steps, the rst step being carried out in contact with water heated by heat transferred from the outgoing air current, the heat and water vapor communicated to said air in said first step being regulated to that required to establish temperature and humidity conditions therein substantially corresponding to those which would be obtained in a properly conditioned air if reduced to its dew point, and the second step being carried out by contacting the air with a heated surface to establish in said intake air the temperature and relative humidity desired.

27. The process of conditioning air for ventilation which comprises heating an intake air current by a portion of the heat of an exhaust air current, partly humidifying the partly heated air current with water vapor formed by heat abstracted from the other of said air currents, subjecting the soheated air current to further heating and humidifying by heat likewise withdrawn from the other of said currents and raised to a higher temperature potential.

28. The process of conditioning air for ventilation which comprises heating an intake air current by heat abstracted from an exhaust air current, humidifying the said air with vapor formed by heat abstracted from the other of said air CHITGDtS SUbjGCU ing the said air current to a second heating and humidifying step by contacting the said air with water heated by heat likewise abstracted from the other of said air currents and raised in its temperature potential to a temperature plane above that of the conditioned air.

29. The process of conditioning air for ventilation which comprises partly heating and humidifying an inlet air current by contacting the same with water which has been heated by heat transferred from an outgoing air current, subjecting the inlet air current to a second heating and humidifying step by bringing the partially heated and humidified current into contact with water which has been heated by heat abstracted from the exhaust current and raised in its temperature potential, and subjecting the said inlet air currents to a third heating step by passing the same in contact with surfaces, the. said surfaces being heated by water which has itself been heated by heat abstracted from the initially warmer of said air currents and raised in its temperature potential by mechanical means.

30. The process of conditioning air for ventilation'which comprises partly heating and humidifying an intake air current by contacting the same with water which has been heated by heat transferred from an exhaust air current, contacting the partially heated and humidified current with water which has itself been heated by the condensation of vapor generated by heat abstraoted from the initially warmer of said air currents, subjecting the intake air currents to a third heating step by passing the same in contact with a heated surface, the said surface being heated by water which has itself been heated by the condensation of water vapor generated by heat abstracted from the initially warmer of said air currents.

31. The process of, conditioning air for ventilation which comprises contacting an exhaust air current with water to partially cool said air current, contacting the soheated water with an intake 'air current to heat said air and to evaporate a portion of said water into said air, contacting a second body of cold water with the partially cooled exhaust air current, continuously transferring the vapor formed from said second body of water into a condensing chamber maintained at a pressure above the vapor tension of water at the temperature of the conditioned air, introducing a third body of water into said condensing chamber to condense said vapor, and subjecting the incoming air current to'heating by the said third body of water in two steps, the first step comprising passing a portion of said third body of water in contact with surfaces in heat transferring relation with said intake air current and the second step comprising joining said portion of said third body of water with the remainder thereof and bringing the combined portions into contact with said intake air current.

32. The process of conditioning air for ventilation which comprises contacting an intake air current with water, contacting said water with an exhaust air current, subjecting a body of water to partial evapora- 120 tion at the expense of its sensible heat, contacting the said cooled water after evapora tion with one of said air currents after the latter has been contacted with said first mentioned water to further cool said air our- 125 rent and to heat said water, returning the so-heated water to said evaporating operation, continuously transferring water vapor from said water being evaporated to a condensing chamber, introducing water into 1 

